📄 rfc1368.txt
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of group number and port number, where port number is an integer in the range 1..rptrGroupPortCapacity. As with groups within a repeater, ports within a group may be sparsely numbered. Likewise, ports may come and go within a group without causing a management reset.3.2. Supporting Functions The IEEE 802.3 Hub Management draft [10] defines the following seven functions and seven signals used to describe precisely when port counters are incremented. The relationship between the functions and signals is shown in Figure 3. The CollisionEvent, ActivityDuration, CarrierEvent, FramingError, OctetCount, FCSError, and SourceAddress output signals defined here are not retrievable MIB objects, but rather are concepts used in defining the MIB objects. The inputs are defined in Section 9 of the IEEE 802.3 standard [9].McMaster & McCloghrie [Page 7]RFC 1368 802.3 Repeater MIB October 1992 +---------+ |Collision|--------------------->CollisionEvent CollIn(X)+>|Event | | |Funct | +--------+ | +---------+ |Activity| | +-------+ |Timing |->ActivityDuration +>|Carrier| +---->|Funct | |Event | | +--------+ DataIn(X)->|Funct |+-----+---------------->CarrierEvent +-------+| | +-------+ +>|Framing|------------>FramingError |Funct | +-------+ decodedData---------->| |+>|Octet | +-------+| |Count |->OctetCount | |Funct | | +-------+ | +-------+ Octet | |Cyclic | Stream +>|Redund.| | |Check |->FCSError | |Funct | | +-------+ | +-------+ | |Source | +>|Address|->SourceAddress |Funct | +-------+ Figure 3. Port Functions Relationship Collision Event Function: The collision event function asserts the CollisionEvent signal when the CollIn(X) variable has the value SQE. The CollisionEvent signal remains asserted until the assertion of any CarrierEvent signal due to the reception of the following event. Carrier Event Function: The carrier event function asserts the CarrierEvent signal when the repeater exits the IDLE state, Fig 9-2 [9], and the port has been determined to be port N. It deasserts the CarrierEvent signal when, for a duration of at least Carrier Recovery Time (Ref: 9.5.6.5 [9]), both the DataIn(N) variable has the value II and the CollIn(N) variable has the value -SQE. The value N is the port assigned at the time of transition from the IDLE state. Framing Function: The framing function recognizes the boundaries of an incoming frame by monitoring the CarrierEvent signal and the decoded data stream. Data bits are accepted while the CarrierEventMcMaster & McCloghrie [Page 8]RFC 1368 802.3 Repeater MIB October 1992 signal is asserted. The framing function strips preamble and start of frame delimiter from the received data stream. The remaining bits are aligned along octet boundaries. If there is not an integral number of octets, then FramingError shall be asserted. The FramingError signal is cleared upon the assertion of the CarrierEvent signal due to the reception of the following event. Activity Timing Function: The activity timing function measures the duration of the assertion of the CarrierEvent signal. This duration value must be adjusted by removing the value of Carrier Recovery Time (Ref: 9.5.6.5 [9]) to obtain the true duration of activity on the network. The output of the Activity Timing function is the ActivityDuration value, which represents the duration of the CarrierEvent signal as expressed in units of bit times. Octet Counting Function: The octet counting function counts the number of complete octets received from the output of the framing function. The output of the octet counting function is the OctetCount value. The OctetCount value is reset to zero upon the assertion of the CarrierEvent signal due to the reception of the following event. Cyclic Redundancy Check Function: The cyclic redundancy check function verifies that the sequence of octets output by the framing function contains a valid frame check sequence field. The frame check sequence field is the last four octets received from the output of the framing function. The algorithm for generating an FCS from the octet stream is specified in 3.2.8 [9]. If the FCS generated according to this algorithm is not the same as the last four octets received from the framing function then the FCSError signal is asserted. The FCSError signal is cleared upon the assertion of the CarrierEvent signal due to the reception of the following event. Source Address Function: The source address function extracts octets from the stream output by the framing function. The seventh through twelfth octets shall be extracted from the octet stream and output as the SourceAddress variable. The SourceAddress variable is set to an invalid state upon the assertion of the CarrierEvent signal due to the reception of the following event.3.3. Structure of MIB Objects in this MIB are arranged into MIB groups. Each MIB group is organized as a set of related objects.McMaster & McCloghrie [Page 9]RFC 1368 802.3 Repeater MIB October 19923.3.1. The Basic Group Definitions This mandatory group contains the objects which are applicable to all repeaters. It contains status, parameter and control objects for the repeater as a whole, the port groups within the repeater, as well as for the individual ports themselves.3.3.2. The Monitor Group Definitions This optional group contains monitoring statistics for the repeater as a whole and for individual ports.3.3.3. The Address Tracking Group Definitions This optional group contains objects for tracking the MAC addresses of the DTEs attached to the ports of the repeater.3.4. Relationship to Other MIBs It is assumed that a repeater implementing this MIB will also implement (at least) the 'system' group defined in MIB-II [4].3.4.1. Relationship to the 'system' group In MIB-II, the 'system' group is defined as being mandatory for all systems such that each managed entity contains one instance of each object in the 'system' group. Thus, those objects apply to the entity even if the entity's sole functionality is management of a repeater.3.4.2. Relationship to the 'interfaces' group In MIB-II, the 'interfaces' group is defined as being mandatory for all systems and contains information on an entity's interfaces, where each interface is thought of as being attached to a 'subnetwork'. (Note that this term is not to be confused with 'subnet' which refers to an addressing partitioning scheme used in the Internet suite of protocols.) This Repeater MIB uses the notion of ports on a repeater. The concept of a MIB-II interface has NO specific relationship to a repeater's port. Therefore, the 'interfaces' group applies only to the one (or more) network interfaces on which the entity managing the repeater sends and receives management protocol operations, and does not apply to the repeater's ports. This is consistent with the physical-layer nature of a repeater. A repeater is a bitwise store-and-forward device. It recognizesMcMaster & McCloghrie [Page 10]RFC 1368 802.3 Repeater MIB October 1992 activity and bits, but does not process incoming data based on any packet-related information (such as checksum or addresses). A repeater has no MAC address, no MAC implementation, and does not pass packets up to higher-level protocol entities for processing. (When a network management entity is observing the repeater, it may appear as though the repeater is passing packets to a higher-level protocol entity. However, this is only a means of implementing management, and this passing of management information is not part of the repeater functionality.)3.5. Textual Conventions The datatype MacAddress is used as a textual convention in this document. This textual convention has NO effect on either the syntax nor the semantics of any managed object. Objects defined using this convention are always encoded by means of the rules that define their primitive type. Hence, no changes to the SMI or the SNMP are necessary to accommodate this textual convention which is adopted merely for the convenience of readers.4. Definitions SNMP-REPEATER-MIB DEFINITIONS ::= BEGIN IMPORTS Counter, TimeTicks, Gauge FROM RFC1155-SMI mib-2, DisplayString FROM RFC1213-MIB TRAP-TYPE FROM RFC-1215 OBJECT-TYPE FROM RFC-1212; snmpDot3RptrMgt OBJECT IDENTIFIER ::= { mib-2 22 } -- All representations of MAC addresses in this MIB Module use, -- as a textual convention (i.e., this convention does not affect -- their encoding), the data type: MacAddress ::= OCTET STRING (SIZE (6)) -- a 6 octet address in -- the "canonical" order -- defined by IEEE 802.1a, i.e., as if it were transmitted least -- significant bit first.McMaster & McCloghrie [Page 11]RFC 1368 802.3 Repeater MIB October 1992 -- References -- -- The following references are used throughout this MIB: -- -- [IEEE 802.3 Std] -- refers to IEEE 802.3/ISO 8802-3 Information processing -- systems - Local area networks - Part 3: Carrier sense -- multiple access with collision detection (CSMA/CD) -- access method and physical layer specifications -- (2nd edition, September 21, 1990). -- -- [IEEE 802.3 Rptr Mgt] -- refers to IEEE P802.3K, 'Layer Management for 10 Mb/s -- Baseband Repeaters, Section 19,' Draft Supplement to -- ANSI/IEEE 802.3, (Draft 8, April 9, 1992) -- MIB Groups -- -- The rptrBasicPackage group is mandatory. -- The rptrMonitorPackage and rptrAddrTrackPackage -- groups are optional. rptrBasicPackage OBJECT IDENTIFIER ::= { snmpDot3RptrMgt 1 } rptrMonitorPackage OBJECT IDENTIFIER ::= { snmpDot3RptrMgt 2 } rptrAddrTrackPackage OBJECT IDENTIFIER ::= { snmpDot3RptrMgt 3 } -- object identifiers for organizing the information -- in the groups by repeater, port-group, and port rptrRptrInfo OBJECT IDENTIFIER ::= { rptrBasicPackage 1 } rptrGroupInfo OBJECT IDENTIFIER ::= { rptrBasicPackage 2 } rptrPortInfo OBJECT IDENTIFIER ::= { rptrBasicPackage 3 } rptrMonitorRptrInfo OBJECT IDENTIFIER ::= { rptrMonitorPackage 1 } rptrMonitorGroupInfo OBJECT IDENTIFIER ::= { rptrMonitorPackage 2 }McMaster & McCloghrie [Page 12]RFC 1368 802.3 Repeater MIB October 1992 rptrMonitorPortInfo OBJECT IDENTIFIER ::= { rptrMonitorPackage 3 } rptrAddrTrackRptrInfo -- this subtree is currently unused OBJECT IDENTIFIER ::= { rptrAddrTrackPackage 1 } rptrAddrTrackGroupInfo -- this subtree is currently unused OBJECT IDENTIFIER ::= { rptrAddrTrackPackage 2 } rptrAddrTrackPortInfo OBJECT IDENTIFIER ::= { rptrAddrTrackPackage 3 } -- -- The BASIC GROUP -- -- Implementation of the Basic Group is mandatory for all -- managed repeaters. -- -- Basic Repeater Information -- -- Configuration, status, and control objects for the overall -- repeater -- rptrGroupCapacity OBJECT-TYPE
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